EPITHELIUM

Major tissue types:

1. Epithelium

2. Connective Tissue.

3. Muscle Tissue.

4. Nervous Tissue.

1. Covering, lining, and protecting surfaces (skin/epidermis)

2. Absorption (intestinal lining)

3. Secretion (glands)

Characteristic ■ Supported by the underlying connective tissue.

■ Innervated (has nerves).

■ Avascular (no blood vessels); blood supply is in supporting connective tissue.

■ High regeneration capacity.

■ Polarized tissue.

Basement membrane (BM)(Epithelium and CT0

■ Is a thin extracellular sheet under epithelium.

■ Synthesized by epithelium and CT

■ Support, attach, and filter.

■ Two layers

1. Basal lamina (Collagen IV, laminin, and Nidogen+perlacan)

2. Reticular lamina (Collagen III and VII)

Basement membrane

CT

Epithelium

Basement membrane

Basement membrane

Electron microscope (TEM) Picrosirius-hematoxylin

Types of Epithelial tissue